Re: [SARA] Need help once again - getting different readings from barebones and cased Sawbird H1

[Martin Pepe]

Q,

How are these terminated ?

And are they just straight thru, no RF switch at the front end ?

A simple 50 dummy load might reveal both ambient (ant) noise & internal noise sensitivity.

I would expect the encased one should be quieter, less radiated noise picked up , but your data says otherwise!

Mjp

 Cloudy skies ? Switch to a longer wavelength! 

Sent from my iPhone

On May 11, 2026, at 10:07 AM, Cathal O'Donghaile <cathalod...@gmail.com> wrote:

Hi Everyone

I'm hoping someone can help me. I've been testing both a barebones H1 and cased H1 filter from Sawbird with AirSpy and I'm getting very different readouts. Most notably, I'm getting a faint hydrogen reading from the barebones and nothing from the Sawbird. Attached are screenshots:

<Screenshot 2026-05-11 141204.png>

<Screenshot 2026-05-11 144757.png>

So 3 things stand out:

• Hydrogen bump on Barebones
• The difference in profile between the 2 devices
• The cased H1 signal is louder sitting above the 50Db line whereas the barebones signal is slight quieter below the 50Db line
  
  Anyone any ideas what might be wrong? Is it possible the cased one isn't picking up the signal from the probe. Just a note I have a copper probe attached.

Would appreciate the help, thank you

Cathal

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<Screenshot 2026-05-11 144757.png>

<Screenshot 2026-05-11 141204.png>